The present invention relates to dental attachment systems or anchors for attaching dental appliances such as overdentures, partial dentures and the like to a remaining non-vital root or to an endosseus implant.
In U.S. Pat. No. 3,787,975 of Max Zuest, an anchor is described which comprises a socket element for insertion in a tooth root and a pivot pin which is embedded at one end in a denture and has an opposite end designed for pivotal snap engagement in the socket element. The pivoting end of the pin is of spherical shape and the socket element has a socket of matching shape.
One problem with existing anchors of this type is that the engaging surfaces of the pin and socket may become worn with repeated removal and insertion of the denture, so that the anchor becomes too loose to provide sufficient retention force for the appliance. Also, breakage or damage to the pin may occur over time, and it is difficult to replace a damaged pin since it is permanently secured to the appliance.